Although car washes have various forms and include various structures, a common type includes a tunnel or the like having various stages which sequentially wash the car as it moves through the tunnel. This type of car wash includes a conveyor that engages one of the tires of the car to move the car through the tunnel without requiring the motive power to be supplied by the car itself. The conveyor includes a series of pusher rollers or the like which travel along a track positioned within a trench below the car wash floor. The pusher rollers are attached to a continuous chain or the like which is driven the length of the conveyor track. Upon admittance of the car into the car wash entrance, the pusher roller protrudes a preset distance above the floor. The protruding roller is then moved forward by the continuous chain and engages the car tire to move the car along the track.
Typically, automatic car wash conveyors include a pair of fixed rails which are positioned adjacent the length of the conveyor track to maintain the car in substantially the center of the car wash tunnel at all stages of the car wash cycle. Additionally, the rails are provided to position the car tire to be engaged by the pusher roller so that the car is moved through the wash cycle. Moreover, since typically the driver is not in the car to steer, the guide rails cooperate with the pusher roller to direct the moving car through the car wash cycle without the need for driver assistance. In most cases, the inner rail acts as a reference line by which the car is centered with respect to the various stages of the car wash within the tunnel.
Different cars are typically provided with tires having different widths, usually in the range of 6 to 13 inches. Thus, for a car wash to accept cars having relatively wider tires, it must provide guide rails which are separated a distance sufficient to admit these tires. This same car wash must also successfully direct cars having smaller width tires. If the guide rails are fixed at the width of the larger tires, it is possible for a smaller tire to turn sideways and run over the guide rails. This may cause the car to move out of the line of the car wash tunnel, possibly causing damage to the car and car wash equipment. Additionally, on some models of car wash conveyors, the pusher roller is limited in width. Thus, if the guide rails are fixed at a width to accept the larger tires, a smaller width tire may be completely missed by the pusher roller or may be pinched between the pusher roller and the guide rail causing damage to the tire or the conveyor.
It is known to provide apparatus within a car wash that adjusts to the width between tires on opposite sides of the car. An example of such adjustment means is a device which applies a brushing action to the side walls of the tires. (See U.S. Pat. Nos. 2,910,202; 3,681,805; and 4,023,228.) It is also known to adjust the position of spray nozzles within a car wash with respect to the sides of a car by sensing the position of the tires. (See U.S. Pat. Nos. 4,178,948 and 4,424,823.) However, the prior art does not include apparatus which adjusts the position of a guide rail on the conveyor to accept tires having various widths while accomplishing the desired function of maintaining the car in position within the car wash and in contact with the pusher roller on the conveyor track.